Impairment of PARK14-dependent Ca ²⁺ signalling is a novel determinant of Parkinson's disease

Abstract

The etiology of idiopathic Parkinson's disease (idPD) remains enigmatic despite recent successes in identification of genes ( PARKs) that underlie familial PD. To find new keys to this incurable neurodegenerative disorder we focused on the poorly understood PARK14 disease locus ( Pla2g6 gene) and the store-operated Ca ²⁺ signalling pathway. Analysis of the cells from idPD patients reveals a significant deficiency in store-operated PLA2g6-dependent Ca ²⁺ signalling, which we can mimic in a novel B6.Cg- Pla2g6 ^ΔEx2-VB (PLA2g6 ex2 ^KO) mouse model. Here we demonstrate that genetic or molecular impairment of PLA2g6-dependent Ca ²⁺ signalling is a trigger for autophagic dysfunction, progressive loss of dopaminergic (DA) neurons in substantia nigra pars compacta and age-dependent L-DOPA-sensitive motor dysfunction. Discovery of this previously unknown sequence of pathological events, its association with idPD and our ability to mimic this pathology in a novel genetic mouse model opens new opportunities for finding a cure for this devastating neurodegenerative disease.

Abstract

PLA2g6 regulates store-operated Ca ²⁺ entry and is linked to Parkinson's disease. Here, Zhou et al find faulty PLA2g6-dependent Ca ²⁺ signaling in idiopathic PD patients, and show that its impairment triggers autophagic dysfunction and loss of dopaminergic neurons in a new PLA2g6 ex2KO mouse model.